1. Field of the Invention
The present invention relates to a display device having a polarizing plate or a circularly polarizing plate. The present invention particularly relates to a display device in which light emitting elements are arranged in matrix and light is emitted from both sides of the light emitting element.
2. Description of the Related Art
A polarizing plate or a circularly polarizing plate is used for a conventional organic EL panel having an organic EL element (For example, Reference 1: Japanese Patent No. 2761453). Such an optical component is provided since external light is reflected in an electrode formed in a display area and that reduces the visibility of an image. Particularly in a state where no image is displayed, an electrode serves as a mirror surface, and the background could be reflected in the electrode. Further, even in a state where an image is displayed, problems such as reduction in contrast or difficulties in displaying black color could arise.
Laminated wave plates such as a laminate of films giving rise to a phase difference of ½ wavelength, which collectively serves as a half wave plate and a laminate of films giving rise to a phase difference of ¼ wavelength, which collectively serves as a quarter wave plate, and a circularly polarizing plate including such a laminated wave plate are generally used (Reference 2: Japanese Patent No. 3174367).
As an example of an electronic device having an EL element in a display area, a cellular phone can be given. A cellular phone of late years has been enabled to display a main screen and a sub screen by providing a panel having an EL element and a panel having a liquid crystal device, or by providing panels having a liquid crystal device in response to the increasing information and functions.
However, in the case where a main screen and a sub screen is displayed by providing such a plurality of panels as described above, an electronic device has become heavy and thick.